An approach on reading musical notes from photos
refer to MNIST on kagle
to train model to recognize given set of notes in your case.



if you start training model will understand pattern depending on bits in your image.

issue comes with blurry images when last 2 sets of pics with minute change. will be difficult task for computer to distinguish.

there is one sure shot method which works almost every time but is resource intensive and needs plethora of data to train. is DNN.

this is my take on your question.